*Excludes Observations that spanned multiple years

Pre 19704
19700
19710
19720
19730
19740
19750
19761
19770
19780
19790
19800
19810
19820
19838
19840
19850
19863
19872
19881
19890
19909
19911
199247
19931
19941
19950
19960
19970
19980
19990
20000
200116
20023
20039
200494
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20171
Total201